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Hi,

I just read some threads/posts about carbon build-ups in the engine head. Evidently, dealers are charging $5k-$8k to fix it. I did a search and nothing shows up as a specific thread. How common is this in the S62 engine? Also, besides the SES light and or failing smog, are there other symptoms? Now that we have some M5s with higher miles, it'd be good to know.

I know the Porsche Carrera has this carbon build-up issue and throws the SES lights. Typically one would replace/rework the valve guides to fix that. How does one fix that problem in the S62 engine? Is there any recommended practice to minimize the build-up in the first place?

Personally, my own M5 had 67k miles and had no smog probelms or SES lights associated with this issue. Also, other E39 series cars, is this an issue with them?

Thanks for the education, as always.

CP
 

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I too have been wondering the same thing. I might be facing this issue.

I wonder if there is a correlation between abnormal carbon build-up and those of us with high oil consumption S62 engines.

It seems that some of us are having powerloss issues (perhaps with pinging) and have not been able to remedy the problem even after changing MAFS, O2's, cam sensors, etc. .
 

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basil said:
I wonder if there is a correlation between abnormal carbon build-up and those of us with high oil consumption S62 engines.
I've seen the heads off twice in my low-mileage 11/99 build M5. Both times I've been surprised at the carbon buildup, that despite using the best gasoline as well as occasional "complete fuel system cleaners" prior to oil changes. My service department says that it happens across all model lines but agrees that the high oil consumption of the early models may contribute to this situation. Of course I now have have an '05 block so we'll see what happens...
 

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People have told me that giving your car the "red line treatment".. driving it up to red line a few times every once and a while helps with burning off carbon buildup? Is that just an old urban legend or is there any truth to it?
 

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Pong,
I think the s62 carbon build up problem is similar to that with the porsche. Carbon clogging the the smog ports eventually causing the ses light. From what i've heard, performance is not effected, just the smog pump and ses light.

Not sure about how common it is, there've been a few posts here and i've seen a couple on other boards, so it doesn't seem very common. I would imagine that a car with higher oil use would have more carbon deposits, so perhaps they go hand in hand. i'm at 66.6k right now, no issues (as far as i know!). My plugs look pretty good last time i took them out.
Mike
 

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Hey HDclown I subscribe to the same "red line treatment" school of thought. I will occasionaly make a red line run with the impression that this somehow clears the intake passages.

I think my belief stems from the old days when my friend's father would "blow out his carburetor" in the old oldsmobile V8 by dropping down a gear in the automatic transmission and flooring it. You would inevitably see a cloud of black smoke coming out of the pipes.

I am fairly certain I am doing more harm than good but its nice to keep the old traditions going.

later.

Michael
 

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mchin said:
Hey HDclown I subscribe to the same "red line treatment" school of thought. I will occasionaly make a red line run with the impression that this somehow clears the intake passages.

I think my belief stems from the old days when my friend's father would "blow out his carburetor" in the old oldsmobile V8 by dropping down a gear in the automatic transmission and flooring it. You would inevitably see a cloud of black smoke coming out of the pipes.

I am fairly certain I am doing more harm than good but its nice to keep the old traditions going.

later.

Michael
When I had my car dynoed, the first couple of runs did in fact produce some black smoke out of the tailpipe. Clearly, the old methodology still helps. That is why a few runs to redline, properly done, under load are probably good for the engine. Best would be a track day!! :M5launch:
Regards,
Jerry
 

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Well, the old carbon build up bug just bit me.

My service advisor just called me and asked how long she could keep the car. I said what's up? She said the SES light is on because the of the carbon build up on the heads, blah, blah, blah. And although my car is a CPO it would not be covered under warranty and my new car warranty ran out a couple of months ago.

BUT!! The BMW reps were at the dealership today and they said they would pay for it this one time "as a good will gesture".

I feel so loved :hihi:.
 

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boplaw said:
because the of the carbon build up on the heads, blah, blah, blah. And although my car is a CPO it would not be covered under warranty
Well, THAT'S a concern.... any explanation as to why the warranty doesn't cover it? If you do get a chance to query the SA once the work is done it'd be useful to know where BMW is on this issue... what is the final $$ count for this fix?

A
 

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boplaw said:
...
BUT!! The BMW reps were at the dealership today and they said they would pay for it this one time "as a good will gesture"...
I'm fairly sure (based on zero actual data) that when BMW does something as a "Good Will Gesture" they either already know that they have a systemic, wide-spread problem (see: Pixel failures in Instrument Cluster), or they need to do research on the problem and your car is being used for that research.
Just my opinion.
 

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I didn't really question her too much once she said they would pay for it as a goodwill gesture.

However, thanks to this board I would have been armed to the gills with enough info to really make them squirm if they said no.

Besides, I get to keep the X3 loaner while mine's in the shop. :thumbsup:
 

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boplaw said:
I didn't really question her too much once she said they would pay for it as a goodwill gesture.

However, thanks to this board I would have been armed to the gills with enough info to really make them squirm if they said no.

Besides, I get to keep the X3 loaner while mine's in the shop. :thumbsup:
It seems to be a problem on older cars maybe due to higher oil consumption; I note yours is an '00. Has anybody had this problem with an '01 or later? I still give BMW high marks for making this a no hassle good will cover on a five year old car.
Regards,
Jerry
 

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gsfent said:
It seems to be a problem on older cars maybe due to higher oil consumption; I note yours is an '00. Has anybody had this problem with an '01 or later? I still give BMW high marks for making this a no hassle good will cover on a five year old car.
Regards,
Jerry
it also seems like more frequent in the south, i wonder if their fuel has anything to do with it?
Mike
 

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I think fuel composition has a lot to do with this, and that driving style / conditions are quite important.

The car was designed in Bavaria. Lots of unrestricted Autobahn, and people with BMWs drive fast daily. The whole culture is quite different from the relaxed, steady pace of a US motorway.

I think all BMW engines benefit from getting thoroughly warmed up and driven to redline under heavy acceleration every few days.

What kills engines are lots of cold-starts followed by short distance driving where the bad fumes that get into the oil past the compression rings doesn´t get to boil off and get out of the oil via the crankcase ventilation before the engine is stopped.

David
 

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A few points that I want to add are that carbon build up in the head can be helped by running the car at a higher speed/rpm for an extended period of time (ie road trip in 5th gear). Also, if you havent driven hard in awhile, the carbon you see blowing out of the exhaust is most likely carbon being freed from the exhaust, and not the engine. Only sustained higher rpm running can help remove carbon in the head.
Although I have no personal experiance with the S62 oil consumption vs. carbon buildup, it is very likely that those two have a lot in common. If anyone has ever lit oil on fire outside an engine then you know it doesnt burn very clean...
:cheers:
 

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This is surely common sense? My clean exhaust advice was somewhat tongue in cheek but is based on truth. If you pussy around with any engine at low revs, not warming it up by doing short journeys, it'll gum up.

I'm also surprised to read how many people when faced with the MAF test talked of the way they felt like it was bad to rev an engine to the redline.

I can honestly say that pretty much every time I drive my car, after it's warmed up it'll be taking many trips to the redline in 2nd/3rd and sometimes 4th gears, and I get full throttle opening as often as I possibly can. I've done this with every car I've owned and I can say that without any exceptions they've all run faster and sweeter the longer I've owned them for.

Plus I've never had any mechanical engine troubles whatsoever, no oil use, no failures, nothing.

I reckon if you're coking up, you should flog the thing some more.

Andy
 

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__Andy__ said:
I reckon if you're coking up, you should flog the thing some more.

Andy
I find it difficult to flog the thing when I'm coking up......

Seriously though, I have had the car for under a year and my commute is all interstate w/ light traffic (thank God), so I do get to run it up pretty good 3 or 4 times a week. I am hopeful that the carbon build up occurred prior to my ownership since it had 39K and little highway use when bought it.
 

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I´ve read somewhere that water can be used to clear carbon deposits.
Anyone know any details of this?

David
 

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Has anybody used the redline fuel system cleaner to see if it can help clean it up.
 
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